1. Field of the Invention
The present invention relates to an L-tartrate of a trans-(-)-4-(4-fluorophenyl)-3-hydroxymethylpiperidine compound, and a process for preparing the same. More specifically, the present invention relates to an L-tartrate of a trans-(-)-4-(4-fluorophenyl)-3-hydroxymethylpiperidine compound which is useful as an intermediate for pharmaceuticals such as paroxetine which is useful, for example, as an antidepressant, and a process for preparing the same.
2. Discussion of the Related Art
Conventionally, a salt of tartranilic acid derivative of a trans-(-)-4-(4-fluorophenyl)-3-hydroxymethylpiperidine compound, represented by the formula (III): ##STR2##
wherein R.sup.2 is hydrogen atom, methyl group or benzyl group, has been prepared by optically resolving a trans-(.+-.)-4-(4-fluorophenyl)-3-hydroxymethylpiperidine compound represented by the formula (IV): ##STR3##
wherein R.sup.2 is the same as defined above, with a tartranilic acid derivative, such as (+)-2'-nitrotartranilic acid or (+)-2'-chlorotartranilic acid, as an optically resolving agent.
However, since the tartranilic acid derivative used as an optically resolving agent is extremely expensive, there is a defect in this process that a complicated procedure of collecting the tartranilic acid derivative after its use and purifying it for reuse is necessitated.
In addition, since the salt of tartranilic acid of the resulting trans-(-)-4-(4-fluorophenyl)-3-hydroxymethylpiperidine compound prepared by using the optically resolving agent has a low bulk density of 230 g/l or so, there arises a defect of poor production efficiency.
In view of the above problems, an object of the present invention is to provide a compound capable of being suitably used as an intermediate for pharmaceuticals such as paroxetine which is useful, for example, as an antidepressant, and a process for preparing the compound using an inexpensive optically resolving agent with high production efficiency.
These and other objects of the present invention will be apparent from the following description.